256 BULLETIN 180, UNITED STATES NATIONAL MUSEUM 



Order DISCOCEPHALI 

 Family ECHENEIDAE 



KEY TO THE GENERA OF ECHENEIDS FROM THE PHOENIX AND SAMOAN ISLANDS 



la. Body and tail slender ; pelvic fins with their inner rays partially connected 

 by a membrane that is mostly free from belly ; pectorals pointed ; lower 

 jaw considerably longer than upper jaw. 



2a. Laminae in disk IX to XI, almost always X Phtheirichthys Gill 



2b. Laminae in disk XXI to XXIX Echeneis Linnaeus 



1&. Body and tail robust ; pelvic fins with inner rays mostly attached to belly ; 

 pectorals rounded ; lower jaw only a trifle longer, or equal to upper jaw ; 

 laminae in disk XII to XIX Remora Forster 



Genus PHTHEIRICHTHYS Gill 



Fhtheirichthys Gill, Proc. Acad. Nat. Sci. Philadelphia, 1862, p. 239. (Type, 

 Echeneis Ivneata Menzies.) 



KEY TO THE SPECIES OF PHTHEIRICHTHYS 



Ic. Dorsal rays 36 to 38 ; anal 37 or 38 



Phtheirichthys multiradiatus, new species 

 16. Dorsal rays 31 to 33; anal 30 to 33 Phtheirichthys lineatus (Menzies) 



PHTHEIRICHTHYS MULTIRADIATUS, new species 

 PlJ^TE 9 



Eolotype. — A specimen (U.S.N.M. No. 115736) 58 mm. in standard 

 length, taken off a barracuda, Sphyraena snodgrassi, that was caught 

 off the reef of Canton Island, April 25, 1939, by Capt. J. N. Lewis. 



In addition, there is one paratype probably taken by the Wilkes 

 Exploring Expedition, for this specimen was in a jar with another 

 echeneid, Phtheirichthys lineatus^ bearing the original number 600, 

 and the quality of paper and size of tag was similar to that used 

 by the Wilkes Exploring Expedition ; our catalog gives Pacific Ocean, 

 and the catalog number is 117864. 



Description. — (Based on the holotype and the paratype, only 

 known specimens. Detailed counts and measurements of the holo- 

 type are given first, followed by those for the paratype in paren- 

 theses. Standard length 58 mm. (113) and total length 68.4 mm. 

 (135.7). All measurements are expressed in hundredths of the 

 standard length.) Length of head 20.2 (19.7); greatest depth of 

 body 7.8 (8.8) ; length of snout 8.5 (8.8) ; diameter of eye 5.2 (4.9) ; 

 distance from tip of snout to posterior edge of maxillary 7.2 (7.4) ; 

 distance from tip of snout to origin of dorsal 54.2 (55.6) ; snout to 

 origin of anal fin 53 (53.7) ; snout to insertion of pelvic fins 21.6 



